When an aircraft is sitting on the ground (as at a terminal gate at an airport), power sometimes is needed onboard the aircraft. For example, a grounded aircraft may need power to run a heating, ventilation, and air conditioning system to control the climate inside the aircraft or to provide lighting inside of the aircraft. Additionally, a grounded aircraft may need power so that instrumentation may be tested and/or operated.
A number of aircraft have an electrical terminal located on the outer body of the aircraft. This terminal is designed to receive an electrical connector (also referred to as a plug) that supplies power through a cable having multiple conductors. The connector typically includes a number of pins or terminals, one for each conductor in the cable. As the connector is plugged into and unplugged from the receiving terminal on the outer body of the grounded aircraft a number of times, the pins and/or conductors can become loose. In such a case, one or more unsafe electrical conditions may arise. For example, an overcurrent situation may develop, causing a potential fire hazard from increased temperatures resulting from the overcurrent operation. As another example, a ground fault may occur, causing an electrical short which can damage equipment on the grounded aircraft as well as equipment on neighboring electrical circuits.